The license management screen allows you to view information about your license. It also allows you to install a license that has been directly provided by Xpand IT.
Licenses provided by Atlassian or acquired in Atlassian's Marketplace should not be installed on this screen. Those licenses should be installed as explained here.
Xporter for JIRA Cloud
License Management screen is not available in Xporter for JIRA Cloud because only Atlassian licenses are allowed and they should be managed in "Manage add-ons" administration page.